High Tide Aquatics

Par meter

supernip

supernip

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I was wondering if someone from the board had a par meter they could possibly lend me during the swap? I made an LED fixture and while Im impressed by its output, I want actual numbers. Here are some pictures, just in case they'd make someone more willing to lend a helping hand.

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sorry about the pictures, they were cell phone pictures. The halide is a 150w reeflux for comparison. The substrate at the bottom of the tank is black.

I live in San Diego so I was only going to bring the fixture if someone could help with the par meter. Let me know, thanks!
 
water causes reflection loss and there is also a minor absorption loss in the "red" side as you go deeper....and complicate it even more, there is an intensity gain with the higher index of water vs air.
 
A bucket will be better than no tank but still only an approximation to your tank. It all depends on how accurate you want your results.
Time average transmission/reflection through the surface (ripples), total internal reflection and boundary transmission will be different than a static bucket with semi-reflective walls.

Again, that is the technical part. If you just want a feel for numbers then a bucket will be "close" (likely will over-predict..and by a lot if you use a white bucket)
 
my tank's a 12in cube. I think the bucket will be ok. Even just air is fine, Im only looking for rough numbers. I still need to find someone with a par meter though
 
(finding someone with a par meter aside) if you want the best "comparison" in a bucket, you will want to use your LED and another light with the bucket technique. Even if your numbers aren't accurate, you can say "this LED light put out 20% more PAR than ___ light)
 
I'd take the readings from the surface (i.e. skip the tank and water) and simply compare that to other fixtures. Will be exact? No, but it will give a good approximation to what it can compare against, i.e. a 70W halide, 150W halide, PC bulb, etc.
 
Air is no help. It could show a PAR of 1300 a few inches away then drop to 150 in water. I've seen it many times, especially with the laser beam focus LEDs tend to have. Even with optics there still is a hot spot up to a few inches (if not more) away.

I have a PAR meter and will bring it to the swap.
 
sfsuphysics said:
I'd take the readings from the surface (i.e. skip the tank and water) and simply compare that to other fixtures. Will be exact? No, but it will give a good approximation to what it can compare against, i.e. a 70W halide, 150W halide, PC bulb, etc.
Click to expand...

Not really. LEDs, T5s, VHOs, etc all have different penetrating power, not to mention dispersion. While a long LED can show a HUGE amount of par right next to it and a HQI may not, 10:1 the HQI will deliver more PAR to the tank over all. Water is needed.
 
clive from nanotuners tells me it's the opposite, leds have better penetrating power. The HQI had a wider, more even spread but at its brightest, it was barely visible compared to the fringe of the LED fixture. With a 12x12 area, my main concern was Raw par and not so much spread
 
Just telling you what I have seen with my own two eyes. Not here to debate nor do I really care.
 
I'm actually blown away they're letting you use SUPERNIP as a handle.
 
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